I could goof you could goof she could goof we could goof you could goof they could goof
V-ing form
I could be goofing you could be goofing she could be goofing we could be goofing you could be goofing they could be goofing
Perfect
I could have goofed you could have goofed she could have goofed we could have goofed you could have goofed they could have goofed
V-ing perfect
I could have been goofing you could have been goofing she could have been goofing we could have been goofing you could have been goofing they could have been goofing
Negation
Simple form
I couldn't goof you couldn't goof she couldn't goof we couldn't goof you couldn't goof they couldn't goof
V-ing form
I couldn't be goofing you couldn't be goofing she couldn't be goofing we couldn't be goofing you couldn't be goofing they couldn't be goofing
Perfect
I couldn't have goofed you couldn't have goofed she couldn't have goofed we couldn't have goofed you couldn't have goofed they couldn't have goofed
V-ing perfect
I couldn't have been goofing you couldn't have been goofing she couldn't have been goofing we couldn't have been goofing you couldn't have been goofing they couldn't have been goofing
Interrogative form
Simple form
could I goof? could you goof? could she goof? could we goof? could you goof? could they goof?
V-ing form
could I be goofing? could you be goofing? could she be goofing? could we be goofing? could you be goofing? could they be goofing?
Perfect
could I have goofed? could you have goofed? could she have goofed? could we have goofed? could you have goofed? could they have goofed?
V-ing perfect
could I have been goofing? could you have been goofing? could she have been goofing? could we have been goofing? could you have been goofing? could they have been goofing?
Interro-negative form
Simple form
couldn't I goof? couldn't you goof? couldn't she goof? couldn't we goof? couldn't you goof? couldn't they goof?
V-ing form
couldn't I be goofing? couldn't you be goofing? couldn't she be goofing? couldn't we be goofing? couldn't you be goofing? couldn't they be goofing?
Perfect
couldn't I have goofed? couldn't you have goofed? couldn't she have goofed? couldn't we have goofed? couldn't you have goofed? couldn't they have goofed?
V-ing perfect
couldn't I have been goofing? couldn't you have been goofing? couldn't she have been goofing? couldn't we have been goofing? couldn't you have been goofing? couldn't they have been goofing?